Photographic apparatus.



A. & L. LUMIERE.

PHOTDGRAPHIC APPARATUS.

Patented Oct. l0, I899.

(Application filed Aug. 17, 1898.) (No Model.) 2 Sheets-Sheet l,

l; 06/773215, Jzgasfia Lava /(Ere, loa Lam/e711 No. 634,560. PatentedOct. l0, I899. A. &. L. LUMIEBE.

PHOTOGRAPH") APPARATUS.

(Application filed Aug. 17, 1898.) (No Model.) 2 Sheets-Sheet 2.

m log I viz/epic:

UNITED STATES PATENT OFFICE.

AUGUSTE LUMIFRE AND LOUIS LUMIFRE, OF LYONS, FRANCE.

PHOTOGRAPHIC APPARATUS.

SPECIFICATION forming part of Letters Patent No. 634,560, dated October10, 1899.

Application filed August 17, 1898. Serial No. 688,792. (No model.)

To all whom it may concern:

Be it known that we,AUG-UsTE LU MIERE and LOUIS LUMIERE, citizens of theRepublic of France, residing at Lyons, France, have invented certain newand useful Improvements in Photographic Apparatus, (for which we haveobtained patent in France, deposited May 31, 1898,) of which thefollowing is a full, clear, and exact specification.

The object of our invention is an improvement in an apparatus of thekind called kinematograph, used to obtain and to project animatedscenes, providing for uniform and continuous rotation in the saidapparatus of the ribbon destined to receive the successive pictures orto project these pictures on a screen. In order to obtain the stabilityor fixedness of the projection in spite of the continual change of thepicture, it is necessary to deviate the projected rays to a certainextent, which varies at every instant according to the position of thepicture at the same instant. lVe obtain this result by placing in theway of these rays a prism of special construction, the tangent of theangle of which Varies in proportion to the movement of the picture bymeans of a mechanism regulated by this very movement.

The accompanying drawings show the disposition used for this purpose.

Figure 1 is a longitudinal sect-ion of the ap paratus. Figs. 2, 3, and 4show the different phases it goes through when at work. Fig. 5 is a planview of Fig. 1.

The film A, 011 which there are the succes sive pictures, descendsvertically from top to bottom under the action of a spool 13, on whichthere are pegs which enter into the perforations that are at fixedspaces of the film. It is guided in the known manner and passes behind awindow O D, the height of which is that of two consecutive pictures. Infront of this window there is a lens 0 and behind it an ordinary lamp,which is not given in the drawings.

In front of the lens is placed the prism with variable angles P, formedof two parallel glass plates at a, disposed so as to be able tooscillate separately on two horizontal axes b b. The glass plates arejoined together by an india'rubber frame in the shape of bellows,

so as to form a water-tight box, the glass plates of which can oscillatefreely all the same. This box filled with water or any other convenientcolorless liquid forms a prism, the faces of which can receive differentinclinations by means of the levers E E, placed on each axis 1).

The levers E are put in motion by a double cam II, placed on ahorizontal shaft F, that is put in motion by drum B by means ofhelicoidal cog-wheels G G. Cam II has the shape of a drum, the sides ofwhich are symmetrically cut out like a helix. The inside of both leversE leans against the sides of this drum. The inside of both levers alsoruns parallel with the glass plates of the prism and passes through thecenter of oscillation Z). The contact of the levers on the cam takesplace through a spring K. Cam II turns around once while one picturepasses. Its breadth and the movement of the helix are such that in themiddle of its course the glass plates at a of the prism are parallel,(see Fig. 3,) whereas at the extreme points of the course they form thelargest angle of deviation at the top or at the bottom, as the case maybe. (See Figs. 2 and 4.)

When the picture I, Fig. 2, occupies the upper part of window 0 D, theangle of prism P is as large as it can be and opens at the top. \Vhenthe picture is in the middle of window, Fig. 3, the glass plates areparallel and there is no deviation. At last, when the picture is at thebottom of the window, the angle of the prism is as large as it can be,but opens at the bottom, Fig. 4. It is therefore possible by dulychoosing the suitable maximum angle of the prism to get the projectionsof the pictures to coincide on the screen in the extreme positions ofFigs. 2 and l with its medium projection, Fig. 3. In the intermediatepositions the coincidence will necessarily take place, since by thisconstruction the linear change of the pictures is in proportion with thetangent of the angle of the prism and the change of the projection onthe screen is in proportion with the angle of the deviation of the rays.Now these two angles (at least within the usual size of the apparatus)vary, so to speak, in the same proportion. At the end of everyrevolution the prism returns suddenly from the position in Fig. 4- tothat of Fig. 2, so that the new picture 1 Fig. -l-, may be projected inits turn.

The size of the extreme angles is fixed by construction according to thefocal distance of the lens;- but it is possible to vary it withincertain limits by lengthening or shortening the arm of the levers E, soas to be able to regulate the apparatus. This result is obtained bylifting or lowering the whole of the upper part of the apparatust'. 6.,the window, the lens, and the prism-placed for that purpose on a movablebearer M. This regulating can be done while making projeetions inobserving the same on the screen.

The apparatus thus disposed can of course be used for obtainingnegatives of animated scenes.

The error committed (if we admit that the deviation is in proportionwith the angle of the prism) is not worth while speaking of, as thevariations of this angle are smaller. There is a means of reducing thiserror by replacing the sole prism by two or more prisms of the samesize, the deviations of which are added together in order to obtain thetotal deviation. The maximum angle of each of these prisms is thusdiminished and the error resulting therefrom likewise. In this caseevery prism will be moved by a helicoidal cam like cam II, but notrunning quite so fast. That will attenuate the sudden fall of levers Eat the end of every turn.

Referring to Figs. 2, 3, and at, the optical axis is represented by theline 50 y. \Vhile the image I descends in a continuous movement behindthe opening 0 D, its projection I remains constantly at the same placeon the screen, because the angle of the prism varies in proportion tothe displacement of the image I. hen the prism P, Fig. 4:, returnssuddenly to the position of Fig. 1, the projection of the image Idisappears under the screen and that of the following image 1 takes itsplace. This sudden change is necessary for the rapid succession of theimages. The purpose is only to preserve at the same point 011 the screenthe projection of the image I while it changes its position from Fig. 2to that of Fig. 4. Thereby it becomes possible to obtain With acontinuous movement of the image I an intermittent movement of theprojection.

Having now described our invention, what we claim as new, and desire tosecure byLetters Patent, is-

An apparatus for projecting chronophotographic pictures comprising aband carrying the pictures, a liquid prism consisting of two movableglass plates joined together by a flexible frame containing the liquid,means for moving the band and means for oscillating the glass platestoward and from each other so that they will lie in planes convergingupwardly in one position and then downwardly in another position,substautiall y as described.

In witness whereof we have hereunto set our hands in presence of twowitnesses.

AUGUSTE LUMI'ICRE. LOUIS LUMIFRE. Witnesses:

Tnos. N. Bnowxn, MAI-HUS V ACIIOS.

